


Light in the Dark (Nyctophobic!Reader x Underfell Sans)

by NonstopCreatorOfNonsense



Category: Undertale (Video Game)
Genre: Alternate Universe, Alternate Universe - Underfell (Undertale), Comfort, Comfort No Hurt, Cuddling & Snuggling, Domestic Fluff, Established Relationship, F/M, Fear, Fever, Fluff, Forehead Kisses, Gentle Kissing, Insecurity, Kissing, Literal Sleeping Together, M/M, Nyctophobia, Originally Posted on Tumblr, Other, Out of Character, Pet Names, Phobias, Reader-Insert, Romantic Fluff, Sharing a Bed, Sick Character, Sickfic, Underfell Papyrus (Undertale), Underfell Sans (Undertale), Underfell Sans/Reader - Freeform, Worried Sans (Undertale), afraid of the dark, fear of the dark
Language: English
Status: Completed
Published: 2020-06-09
Updated: 2020-06-09
Packaged: 2021-03-27 00:09:07
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,096
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30114165
Author URL: https://archiveofourown.org/users/NonstopCreatorOfNonsense/pseuds/NonstopCreatorOfNonsense
Summary: Sans notices that you've caught a fever and has taken it upon himself to look after you. While doing so, he happens to discover that you're nyctophobic
Relationships: Underfell Sans/Reader
Kudos: 3





	Light in the Dark (Nyctophobic!Reader x Underfell Sans)

**Author's Note:**

> I apologize in advance if this seems to skip around or if some parts don't really make sense ^^" I originally wrote this as a request on Tumblr, and since I didn't know how to add in a 'read more' link on the app at the time, I didn't want this to be ungodly long

The day had felt rather long, and in your opinion, felt nearly the same as every other day. You had woke up, ate some food and got dressed, and then you proceeded to sprawl out on your bed, enjoying the silence while it lasted. It didn’t matter what day it was; It could be a Tuesday, a Thursday, or even a _Sunday_ , but you always seemed to have some sort of uncanny ability to predict when your day was about to become much more hectic.

And at the time, that’s exactly the feeling you were beginning to have. Today would be interesting, without a doubt.

When Papyrus invited himself into your home without so much as a warning, you’d let out a deep sigh, and let him spout off whatever nonsense he wanted to in silence. Deciding to simply tune him out, it came as a surprise to you when the spouting came to an abrupt halt and you were scooped up off the ground, whisked away from the humble abode you called your home. As it turned out, today was recalibration day. Though it pained you to admit, your beloved boyfriend couldn’t really… Be counted on to recalibrate his. That was where you came in, though. While Papyrus busied himself with checking over his own puzzles, you accompanied Sans, hoping to give him some encouragement to work just a _tad bit_ faster. After what felt like an eternity, all the recalibration was finally finished. Papyrus was satisfied enough with your work, much to your surprise, that you were dismissed. This is what led you to your present situation. You were currently at the skeleton brothers’ house, curled up on the old, lumpy sofa in the living room. Sans was beside you, an arm wrapped around you and holding you close to himself while his free hand held the tv remote as he idly flipped through the available channels in search of something to watch. You both knew that wasn’t likely, but he didn’t put the remote down and you chose not to say anything.

Laying your head on his shoulder, your lips curled into a soft smile as you felt his bony hand leave your side and make its way to your head, where he began to gently run his fingers through your hair. As you let your eyes drift shut, you heard him chuckle softly, his gruff voice holding an all too familiar teasing tone, “Well _someone_ seems to like bein’ pet.” You hummed, lips still curled into a slight smile as you shrugged, opening your eyes to look up at him, “Maybe I do, maybe I don’t. That’s for me to know and _you_ to find out.” Playfully raising a brow bone, he offered you his signature sharp toothed grin, “And what do I gotta do ta’ find out, Hot Stuff?” You felt heat rush to your cheeks, followed by the sound of Sans laughing again. His laughter only caused your blush to darken further, and you puffed your cheeks out and pouted, _“Saaaaans,_ you ass! You _know_ I get embarrassed when you start in with the pet names.” The skeleton tilted his head, his grin turning smug as he lightly pinched your cheek, “Mmn, nope. I have no clue what yer talkin’ about, Sweetheart.”

Your playful dispute lasted about… _Maybe_ ten to fifteen minutes before he sighed, lightly pressing his teeth to your forehead. It was meant to be a kiss, but the way he froze and briefly tensed up had you raising an eyebrow in confusion. You didn’t even get the chance to ask what was wrong before he cut in, pulling his face away from yours and replacing his teeth with his hand, “Holy shit… You’re burnin’ up. Are you feelin’ ok, Sweetheart?” You nodded softly, an eyebrow still arched, “Uhh…. _Yeah_ , I guess so. Why? Something wrong?” He made a soft sound of confirmation, “Yeah, there is. You got a fever, Y/N.” You tried to convince him that you were fine, but the irritated, unimpressed stare you received in response was enough to tell you that he wasn’t buying it. Not in the _slightest_. Much to your chagrin, you were corralled upstairs to his room and lightly pushed back onto the bed. You turned around to argue that you were perfectly fine with returning home to do your recuperating there, but he was gone already. You rolled your eyes and flopped down onto the bed on your back, staring up at the ceiling.

This was _Sans_. He probably wasn’t going to listen to you, no matter what you said or did. You loved him with every fiber of your being, but his unyielding stubbornness had the tendency to become rather aggravating at times.

It wasn’t much longer before he returned, a bowl in hand as he sat beside you. Although you’d just managed to get comfortable, you sighed and sat up, quirking an eyebrow at the bowl and it’s contents before lifting your gaze to his face, offering him a tiny smile and speaking with a playful tone, “Ok, that’s it. Who are you and what have you done with my favorite bonehead?” It was his turn to roll his eyes, grumbling something under his breath. He nearly shoved the bowl of soup into your hands, falling silent after a moment. It took a little gentle prodding and more puns than you’d ever cranked out in one sitting before, but eventually, he returned to his normal seemingly careless, stubborn, and punny self. You ate as much of the soup as you could before he took the bowl from you and vanished with it, presumably to put it in the fridge. As soon as he returned, you were immediately being told to lay down and go to sleep, and you reached out to snag his sleeve, stopping him before he could make a beeline for the light switch.

Your heart skipped a beat and your pulse seemed to spike as a realization dawned on you: You _weren’t_ at home. There’d be _no_ light, only darkness while you slept. Memories and images flickered in your mind and you did your best to force them back, offering Sans a weak smile, “I um… I’m not really tired yet. You wanna play cards or a videogame or something? I’ll even let you pick, if you want.” The skeleton stared at you for a moment, his expression unreadable, “Listen to me, Sweet Pea. You have a fever. You’re sick, and you should be _resting_. Even if you’re not tired, you need to at least _try_ to get some sleep.” Your weak smile instantly faded and you stared up at him, your gaze almost pleading, “Could we _maybe_ keep the light on or something then, please? I… Wouldn’t want you to trip or get hurt or anything, if you had to walk through the dark.” He watched you for a moment, waving you off dismissively as he gently slipped free from your grasp and headed for the light switch.

Everything had happened so fast; Your pulse picked up, your eyes went wide, and your breathing began to quicken. As you reached out and began to blindly search for him with your hands, you called out to him, your voice shaking, _“S-Sans?…”_ You could hear him release a faint sigh, and as a set of two familiar scarlet eye lights focused their attention on you, you continued to reach for him, “Sans please, _please_ stay with me, I don’t… I can’t-” The skeleton approached the bedside, sitting beside you and wrapping an arm around your waist, the soft glow from his eye lights just barely bright enough for you to see the concern on his face as spoke, “Hey, hey. Sweetheart, what’s wrong?… You’re actin’ so scared all of a sudden, did I miss somethin’?” Pressing as close to him as you could, you clung to him and slowly shook your head, “I… I just-” He made a soft sound, almost in consideration, before you were gently lifted into his lap. Hands still balled into fists as you wrapped your arms around him and clung to his shirt again, you fell silent. The skeleton frowned as he watched you, his gruff voice softer than you had been expecting, “If ya don’t wanna talk about it, that’s ok too. I’d like it if ya _would_ though so I can figure out how to help you.” Taking a deep breath, your hesitation lasted no longer than a mere moment before you responded, your voice a soft mumble, “I… Have nyctophobia…”

Arching a brow bone, he tilted his head as he continued to watch you, “…Is that like… A fear of the dark or somethin’?” A lump began to form in your throat and you felt your bottom lip tremble as you slowly nodded, not quite sure you were able to force out any words at the moment. You were expecting him to crack a joke or make some sort of belittling comment about your fear of the dark; Sans was a little rough around the edges at times, but he’d always been so sweet to you, despite that. You had no reason to assume that he’d laugh at you, but the fear was there, and it rapidly became too much for you. As a single tear rolled down your cheek, he gently cupped your face, his thumb brushing away the small bead as he very carefully tipped your head up, prompting you to look at him. When you did, you saw _not a single ounce_ of amusement or entertainment on his face. He was completely serious, his hand still on your face as he murmured, “Hey no, no cryin’, Sweet Pea… Please don’t cry.” Though he meant well, your bottom lip trembled again, and suddenly, more tears were staining your cheeks.

Through your tears, you stayed cuddled up to him, unable to speak louder than a whisper, “I’m sorry… I just thought you were gonna call me a baby because of it, or say I was just being stupid or something.” Brow bones knit into a look of confusion, he murmured again, “And why the hell would I do somethin’ like that?…” You laid your head on his shoulder and weakly shrugged, gently resting your hand atop his, “I dunno… It’s just how everyone else has always reacted to it before…” Sans scoffed, a single brow bone raising a small bit, “Yeah, about that. Y'wanna know somethin’, Sweetheart?” You made a sound in the back of your throat, letting him know you were listening before he continued, offering you a slight smile, “I'mnot _‘everyone else’_ , am I?… I’m _me_ , and I care about ya, even if sometimes… I’m not the best at lettin ya know that.”

Upon hearing his words, you felt your lips curl into a tiny grin, “I know… You’re _you_ , Sans, and even if you’re _kind of an ass_ sometimes, I love you.” The skeleton’s cheekbones dusted a faint shade of red and his smile almost became sheepish. Hoping you wouldn’t notice his vague embarrassment, he leaned closer, softly pressing his teeth to your lips and kissing you. It was rather short and sweet compared to the way he _normally_ seemed to like kissing you, but… You liked it anyway. As he broke away from the kiss, he cradled you close to himself and rested his head atop yours, his voice a whisper, “I love ya too, Sweetheart…”

There was a moment of silence before you raised an eyebrow, still smiling to yourself as you playfully asked, “Does that mean you’ll stay here with me, then?” Sans chuckled, flopping down onto his back and pulling you down along with him, and you let out a surprised squeak. Moving one hand to your hip, he began to card the other through your hair, releasing a deep sigh, “A’ course… Do I _look like_ ’m in any position to go anywhere?” Grinning, you leaned into his touch, now feeling much more at ease, “Thanks, Sans… You’re the best.” The skeleton couldn’t help but smile again, his voice a whisper, “I try, Sweetheart… ’M happy ya think so.” You closed your eyes, and it wasn’t long before you began to feel yourself on the verge of slipping into a peaceful slumber. As you passed into the realm of the unconscious, Sans silently watched over you, unable to help smiling as he admired the peaceful expression you wore.

Delicately touching your face again, he whispered, “I love you, Y/N… And I’ll be your light in the dark.”


End file.
